I'd like to realise low level of multi-touch protocol used in apple device (as I now it called multi-touch (MT) multi-touch-protocol ) over HID on STM32 microcontroller. I sniff all USB descriptor of Magic Trackpad 2 using USBLyser. It include "Device Management" intarface,"Trackpad" interface, "Actuator" interface, "Accelerometer" interface. I show report descriptor of "Trackpad" interface
Item Tag (Value) Raw Data Usage Page (Generic Desktop) 05 01
Usage (Mouse) 09 02
Collection (Application) A1 01
Usage (Pointer) 09 01
Collection (Physical) A1 00
Usage Page (Button) 05 09
Usage Minimum (Button 1) 19 01
Usage Maximum (Button 3) 29 03
Logical Minimum (0) 15 00
Logical Maximum (1) 25 01
Report ID (2) 85 02
Report Count (3) 95 03
Report Size (1) 75 01
Input (Data,Var,Abs,NWrp,Lin,Pref,NNul,Bit) 81 02
Report Count (1) 95 01
Report Size (5) 75 05
Input (Cnst,Ary,Abs) 81 01
Usage Page (Generic Desktop) 05 01
Usage (X) 09 30
Usage (Y) 09 31
Logical Minimum (-127) 15 81
Logical Maximum (127) 25 7F
Report Size (8) 75 08
Report Count (2) 95 02
Input (Data,Var,Rel,NWrp,Lin,Pref,NNul,Bit) 81 06
Report Count (4) 95 04
Report Size (8) 75 08
Input (Cnst,Ary,Abs) 81 01
End Collection C0
End Collection C0
Usage Page (Digitizer) 05 0D
Usage (Touch Pad) 09 05
Collection (Application) A1 01
Usage Page (Vendor-Defined 1) 06 00 FF
Usage (Vendor-Defined 12) 09 0C
Logical Minimum (0) 15 00
Logical Maximum (255) 26 FF 00
Report Size (8) 75 08
Report Count (16) 95 10
Report ID (63) 85 3F
Input (Data,Var,Abs,NWrp,Lin,NPrf,NNul,Bit) 81 22
End Collection C0
Usage Page (Vendor-Defined 1) 06 00 FF
Usage (Vendor-Defined 12) 09 0C
Collection (Application) A1 01
Usage Page (Vendor-Defined 1) 06 00 FF
Usage (Vendor-Defined 12) 09 0C
Logical Minimum (0) 15 00
Logical Maximum (255) 26 FF 00
Report ID (68) 85 44
Report Size (8) 75 08
Report Count (1387) 96 6B 05
Input (Data,Ary,Abs) 81 00
End Collection C0
As i understand, MT-A (B) protocol is working over HID (Vendor-Defined part of report descriptor). Could somebody help me find the description of this protocol, or tell about it.
Or access to this information is denied?
